Skyrocketing gas prices, mind-boggling bills, salaries stuck for years. Thus, to get to the end of the month, next winter many families could be forced to keep the heating off or to a minimum. A choice that benefits your wallet, but which risks damaging your health. In particular, it seems that living in a house that is too cold, with a temperature below 18 degrees, can harm those with high blood pressure (hypertension).
This happens because, when the mercury is lowered, the caliber of the blood vessels decreases (vasoconstriction), resulting in an increase in blood pressure. The Smart Wellness Housing study, published in Hypertension Research and conducted, between 2014 and 2019, by a group of researchers from the School of Environment and Society of the Tokyo Institute of Technology, Japan, on over 2,500 families, for a total of 5 thousand people.
Elderly and women more sensitive to temperatures
During the past winters, the research participants measured, using automated monitoring sensors provided by the scholars, the temperature in three rooms of the house (living room, dressing room, bedroom) and their blood pressure, twice in the morning and twice in the morning. evening, keeping a diary for two weeks.
The survey found that the average temperatures were 16.8, 13 and 12.8 degrees respectively in the living room, locker room and bedroom, while the minimum temperatures were 12.6, 10.4 and 11.2 degrees. In particular, the minimum temperatures were below 18 degrees in over 90% of homes, especially in those of low-income families and people who live alone.
An inverse association
These data were then related to blood pressure values, showing an inverse association: in practice, this means that the lower the temperatures, the higher the pressure and vice versa. In detail, the experts noted that the pressure was more sensitive to temperature in the morning, recording an increase of 8.2 millimeters of mercury (mmHg) for a decrease of 10 degrees, compared to the evening, when with the same temperature reduction the increase recorded was 6.5 mmHg. They also found that sensitivity was higher in older residents (aged 57 and over) and in women.
Unstable pressure
However, it is not only high blood pressure that damages the cardiovascular system, but also unstable blood pressure, that is, with large fluctuations throughout the day. In particular, the study found that participants living in homes with a slight temperature range between day and night (less than 1 degree) showed lower blood pressure variability than those living in homes with a greater difference in temperature ( 4 degrees or more).
The positive effects of thermal insulation
At a later stage, the experts evaluated the same parameters after some houses were subjected to thermal insulation, in which external walls, floor, roof were insulated; to replace single-glazed windows with double-glazed ones. Thanks to these interventions, the home temperature increased by 1.5 degrees, reducing blood pressure by 3.1 mmHg. This shows that even small increases in temperature can be very effective in keeping blood pressure under control, a fundamental element especially for those with a high cardiovascular risk.
Minimum 18 degrees recommended
“Our research has shown that living in adequate housing is important for preventing hypertension and decreasing mortality caused by cardiovascular disease – he explained. Wataru Umishio, researcher at the Tokyo Institute of Technology and coordinator of the study -. Currently, experts agree in recommending a minimum home temperature of 18 degrees, as also recommended by the guidelines for housing and health published in 2018 by the World Health Organization (WHO) “.